Update maximum code line length to 80

This is required due to increasing the code font size. We could
probably get away with a slightly higher limit (maybe even 86 or 87)
but 80 feels suitably "standard" and may avoid problems in the
future if indentation or font sizes are tweaked.

Author: jskeet

tools/MarkdownConverter/Converter/MarkdownSourceConverter.cs

@@ -21,7 +21,7 @@ public class MarkdownSourceConverter
         /// <summary>
         /// The maximum code line length that's allowed without generating a warning.
         /// </summary>
-        public const int MaximumCodeLineLength = 95;
+        public const int MaximumCodeLineLength = 80;
 
         private const int InitialIndentation = 540;
         private const int ListLevelIndentation = 360;